[SD987]

Short answer...improved cooling system. Long answer:

The new Boxster retains the familiar cross-flow cylinder head cooling system from the first Boxster for efficient and even distribution of coolant to all cylinders. The water pump, now a carry over part with the new 911 Carrera/S, ensures a higher coolant flow rate. The Boxster and Boxster S versions with manual gearbox are fitted with two radiator modules located as before in the wings ahead of the front wheels. These have been increased both in area (approx. 5 %) and depth (approx. 20 %) and are identical with the radiator modules of the new 911 Carrera/S. The two more powerful electric fans also feature automatic requirement-driven control and a modified air flow concept.This ensures an optimised air flow and an aerodynamically optimised cooling-air system. This new feature permits infinite control of the fan speed as a function of the coolant temperature and the system pressure in the air conditioning system instead of two-stage control. It has the advantage of requiring less current and therefore creates less of a load on the vehicle electrical system as well as being less noisy. The new line layouts for the radiator in the front end and the reworking of the radiator connections have reduced the sensitivity of the new Boxster models to damage and hence reduced repair costs. The use of cost-effective brackets with desired break points prevents the radiator module being damaged in a slight collision, for example. When it comes to repair, the damaged plastic carriers can be replaced and the radiator module re-mounted. Furthermore the use of quick couplings throughout the cooling system pipework has reduced the amount of repair work required in the event of damage, again resulting in lower repair costs. On the Boxster S with Tiptronic S, an additional third radiator is used in the front end of the vehicle to facilitate cooling of the automatic transmission oil via an additional oil-water heat exchanger in the common water circuit. The improvement in the efficiency of the water-cooling system means that the smaller oil/water heat exchanger (engine-oil cooling) of the 2.7 litre engine can now also be used in the 3.2 litre engine, which has resulted in a reduction in weight of 360 g/0.79 lbs.